Lighting fixture with prismatic reflector

ABSTRACT

An overhead lighting fixture including a planar base member with a hollow open ended housing secured at one end to the underside of the base member and extending downwardly therefrom. A light source in the form of a pendant incandescent lamp is secured to the underside of the base member and extends downwardly therefrom interiorly of the housing. A hollow, peripheral reflector is disposed interiorly of the housing and is secured to the lower portion of the housing below the light source. A lens is disposed between the light source and the reflector, the lens reflector having prisms formed therein to direct light from the light source downwardly and outwardly through the lens to the reflector and thence downwardly and outwardly in an opposite direction at a substantial angle to the vertical to illuminate a large horizontal area below the fixture.

United States Patent 1,746,852 2/ 1 930 Champeau lnvcntor Joseph L. Jafie, Jr.,

Shaker Heights, Ohio Appl. No. 735,385 Filed June 7,1968 Patented Feb. 9, 1971 Assignee Perfeclite, Inc.

Cleveland, Ohio a corporation of Ohio. by mesne assignments LIGHTING FIXTURE WITH PRISMATIC REFLECTOR 1 1 Claims, 13 Drawing Figs.

US. Cl 240/78, 240/106 Int. Cl F2lv 5/02, F2lv 7/00, F2lv 13/00 Field of Search 240/ 1 06, 106.1, 78, 78H, 78HAS References Cited UNITED STATES PATENTS 1,794,839 3/1931 Dorey 3,030,498 4/1962 Jones ABSTRACT: An overhead lighting fixture including a planar base member with a hollow open ended housing secured at one end to the underside of the base member and extending downwardly therefrom. A light source in the form of a pendant incandescent lamp is secured to the underside of the base member and extends downwardly therefrom interiorly of the housing. A hollow, peripheral reflector is disposed interiorly of the housing and is secured to the lower portion of the housing below the light source. A lens is disposed between the light source and the reflector, the lens reflector having prisms formed therein to direct light from the light source downwardly and outwardly through the lens to the reflector and thence downwardly and outwardly in an opposite direction at a substantial angle to the vertical to illuminate a large horizontal area below the fixture.

PATENTEUFEB 9km saw u or 5 INVENTORL Jszww L. JZ'FFE HTTO/PNE LIGHTING FIXTURE WITII PRISMA'IIC REFLECTOR This invention relates to lighting fixtures and more particularly to lighting fixtures having a downwardly acting lens and refractor combination.

There has long been a need for a highly efficient, easily maintained, overhead luminaire that provides even, high level illumination over a very large area. Prior luminaires or fixtures usually provide a glaring light of high brightness and illuminate only a limited area immediately below the fixture. Additionally, such prior fixtures are also subject to deterioration, discoloration, dust, dirt and grime.

Therefore, it is an object of the invention to provide a luminaire effecting even, high level illumination over a very large area whereby there is a dispersal of light rays over an area greater than the aperture of the optical train.

A further object of the invention isto provide a luminaire of the above type emitting even, luminous light, free of harsh glare.

A further object of the invention is to provide a luminaire of the above type that is substantially free from deterioration, discoloration, dust and dirt.

A further object of the invention is to provide a luminaire of the above type that is simple in construction, inexpensive to manufacture, and highly effective in operation.

Briefly, the foregoing objects are accomplished by the provision of an overhead fixture or luminaire including a flat base attached to a room ceiling, with a hollow open ended housing secured at one end to the base and extending downwardly from the ceiling. A pendant incandescent lamp is secured to the base and extends downwardly therefrom interiorly of the housing. A hollow, peripheral cone-shaped refractor is disposed interiorly of the housing and is secured to the lower edge of the housing below the lamp. A lens is disposed between the lamp and the refractor and rests on the refractor. The lens and refractor have coacting prisms formed therein for directing light from the lamp directly downwardly, and also downwardly and outwardly through the lens to the refractor and thence downwardly and outwardly in an opposite direction to illuminate a large area below the fixture. In one form of the invention, the lens is circular in planar configuration and the refractor is configured in the shape of a frustum of a hollow cone. In another form of the invention the lens is square and the refractor is configured in the shape of a frustum of a four-sided hollow pyramid. A reflector may be provided above the lamp to direct light therefrom to and through the lens. The housing may be removably secured to the base by detachable coil springs.

With this construction, disassembly of the fixture for lamp replacement is substantially simplified. The lens-refractor combination provides glare-free, even illumination over a very wide area. The fixture is virtually maintenance-free and the glass cone is not subject to deterioration or discoloration and is least affected by dirt and grime.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the drawings wherein:

FIG. I is a vertical sectional view of a luminaire constructed in accordance with the invention;

FIG. 2 is a view taken along the line 2-2 of FIG. 1;

FIG. 3 is a view taken along the line 33 of FIG. 1;

FIG. 4 is an enlarged top view of a peripheral portion of the refractor shown in FIG. 2;

FIG. 5 is a vertical sectional view of the lower half of a modified luminaire of the invention;

FIG. 6 is a view taken along the line 6-6 of FIG. 5;

FIG. 7 is a view taken along the line 7-7 of FIG. 5;

FIG. 8 is an enlarged view taken along the line 8-8 of FIG. 7;

FIG. 9 is an enlarged view broken side view of a part of the upper peripheral portion of the refractor shown in FIG. 5;

FIG. 10 illustrates another means of mounting the Inminaire;

FIG. I1 illustrates a further means of mounting the luminaire;

FIG. I2 illustrates a still further means of mounting the luminaire; and

FIG. 13 is a schematic diagram illustrating the flow of light through the luminaires of FIGS. 1 and 5.

Although the invention is shown and described herein with reference to ceiling lighting fixtures of the downlight" type, it will be understood that it may be applied to any type of indoor or outdoor lighting fixture or luminaire.

Referring first to FIG. I there is shown a luminaire or overhead lighting fixture of the invention including a planar base member 10 secured to the ceiling 12 by the screws 14, a hollow open ended housing I6 secured to the base, a hollow peripheral refractor I8 resting on the inwardly extending bottom edge flange 20 of the housing, a lens 22 resting on the refractor, and a light source in the form of a pendant incandescent lamp 24 secured in the lamp socket 26 which, in turn, is secured to the base 10 by the screws 28. A specular, parabolic reflector 32 may be provided above the lamp 24, such reflector being attached to the base 10 by the brackets 34. The reflector directs light from above the lamp 24 to and through the lens 22. The housing I6 may be removably secured to the base 10 by the tensioned coil springs 36 which are secured at their lower ends to the housing hooks 37 and at their upper ends to the base hooks 38.

The lens 22 has a plurality of preconfigured prisms 42 formed in its under surface, and the refractor 18 has a plurality of prisms 44 formed on its inner surface. The coacting prisms 42 and 44 are constructed to direct light through the fixture in the manner shown by the arrows in FIG. 13. Specifically, light from the lamp 24 is directed downwardly and outwardly through the lens 22 to the refractor I8 and thence downwardly and outwardly in an opposite direction at a substantial angle to the vertical. Light passing through the central portion or bubble 45 of the lens 22 is directed downwardly. With this construction, a very large horizontal area immediately below the fixture is illuminated. The refractor effects a pattern of concentric interior rings and radial vertical prisms to redirect light out from the sides for even, high-level illumination.

In another form of the invention, the lens 22 may be removed from the fixture, whereby the lamp 24 and the refractor 22 distribute light substantially as above-described with reference to FIG. 13.

In the preferred form of the invention, the sides of the refractor extend downwardly and outwardly at an angle of (FIG. I) to the horizontal, although angles of 75 to have proved to be satisfactory.

In the FIG. 1 structure, the housing I6 is annular in crosssectional configuration, with the lens 22 being annular in planar configuration, and the refractor 18 is configured in the shape of a frustum of a hollow cone.

In the FIG. 5 modification, the housing 52 is rectangular in cross-sectional configuration, with the lens 54 being rectangular in planar configuration, and the refractor S6 is configured in the shape of a frustum of a four'sided hollow pyramid. The lens 54 contains prisms 55 of the type aforedescribed in the FIG. 1 structure. Likewise, the refractor 56 contains prisms 57 of the same type as those in refractor 18.

For more effective light control, the upper portion of the outer surface of the refractors l8 and 56 is serrated. Specifically the refractor 18 contains the vertical prisms or ribs 62 (FIG. 4) on its outer surface, and the refractor 56 contains the vertical prisms or ribs 64 (FIG. 9) on its outer surfaces. Likewise, the upper surface of the lenses 22 and 54 are pebbled. For example, the upper surface of the lens 22 contains the pebbles 72 (FIG. 2), and the upper surface of the lens 54 contains the pebbles 74 (FIG. 6).

FIG. 8 illustrates preferred cross-sectional dimensions of the lens prisms. The dimension X should be approximately one-fourth inch and the dimension Y should be approximately one-sixteenth inch. Preferably, the angle 22" is approximately 10 The luminaire of the invention may be mounted in various positions. As shown in FIG. the housing 16 may be partially recessed into the ceiling 12, while in FIG. 11 the housing is completely recessed into the ceiling. FIG. 12 illustrates a pendant method of mounting wherein the fixture is suspended from the ceiling 12 by the rod 80, such rod being secured to ceiling by the plate 82.

Thus, there is provided an overhead luminaire that not only illuminates a very wide area directly therebelow, but is virtually maintenance-free in that it is free from discoloration and from accumulating dirt, dust and grime. Such luminaire reflects light that is normally trapped in baffled fixtures, and eliminates harsh glare normally associated with exposed specular reflectors.

The tenns and expressions which have been employed are used as terms of description, and not of limitation, and there is no intention, in the use of such tenns and expressions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

lclaim:

1. An overhead lighting fixture comprising, a planar base member, a hollow open ended housing secured at one end to the base member and extending downwardly therefrom, a light source secured to the underside of the base member and extending downwardly therefrom interiorly of the housing, a downwardly and outwardly tapering peripheral prismatic reflector disposed interiorly of the housing and secured to the lower portion of the housing below the light source, the sides of the prismatic reflector extending downwardly and outwardly at a substantial angle to the horizontal, said prismatic reflector having reflector prisms formed therein to direct light from the light source downwardly and outwardly in an opposite direction at a substantial angle to the vertical to illuminate a large horizontal area immediately below the fixturei 2. The structure of claim 1 and further including a lens disposed between the light source and the refractor, said lens having prisms formed therein coacting with said refractor prisms to direct light from the light source downwardly and outwardly through the lens to the refractor and thence downwardly and outwardly in an opposite direction at a substantial angle to the vertical to illuminate a large horizontal area immediately below the fixture.

3. The structure of claim 2 wherein the sides of the refractor extend downwardly and outwardly at an angle of 75 to 95 to the horizontal.

4. The structure of claim 2 wherein the sides of the refractor extend downwardly and outwardly at an angle of 85 to the horizontal.

5. The structure of claim 2 wherein said housing is annular in cross-sectional configuration, said lens is annular in planar configuration, and said refractor is configured in the shape of a frustum of a hollow cone.

6. The structure of claim 2 wherein said housing is rectangular in cross-sectional configuration, said lens is rectangular in planar configuration, and said refractor is configured in the shape of a frustum of a four-sided hollow. pyramid.

7. The structure of claim 2 wherein a reflector is disposed above said light source to direct light therefrom to and through the lens. I

8. The structure of claim 2 wherein said fixture is adapted to be secured to a room ceiling, said base being secured directly to such ceiling.

9. The structure of claim 2 wherein said fixture is adapted to be secured to a room ceiling, said housing being secured directly to such ceiling.

10. The structure of claim 2 wherein said fixture is adapted to be pendantly secured to a room ceiling.

11. The structure of claim 2 wherein said housing is annular in cross-sectional configuration, said lens being annular in planar configuration and resting on the refractor, said refractor being configured in the shape of a frustum of a hollow cone, the sides of said refractor extending downwardly and. outwardly at an angle of to the horizontal, there being a 

1. An overhead lighting fixture comprising, a planar base member, a hollow open ended housing secured at one end to the base member and extending downwardly therefrom, a light source secured to the underside of the base member and extending downwardly therefrom interiorly of the housing, a downwardly and outwardly tapering peripheral prismatic reflector disposed interiorly of the housing and secured to the lower portion of the housing below the light source, the sides of the prismatic reflector extending downwardly and outwardly at a substantial angle to the horizontal, said prismatic reflector having reflector prisms formed therein to direct light from the light source downwardly and outwardly in an opposite direction at a substantial angle to the vertical to illuminate a large horizontal area immediately below the fixture.
 2. The structure of claim 1 and further including a lens disposed between the light source and the refractor, said lens having prisms formed therein coacting with said refractor prisms to direct light from the light source downwardly and outwardly through the lens to the refractor and thence downwardly and outwardly in an opposite direction at a substantial angle to the vertical to illuminate a large horizontal area immediately Below the fixture.
 3. The structure of claim 2 wherein the sides of the refractor extend downwardly and outwardly at an angle of 75* to 95* to the horizontal.
 4. The structure of claim 2 wherein the sides of the refractor extend downwardly and outwardly at an angle of 85* to the horizontal.
 5. The structure of claim 2 wherein said housing is annular in cross-sectional configuration, said lens is annular in planar configuration, and said refractor is configured in the shape of a frustum of a hollow cone.
 6. The structure of claim 2 wherein said housing is rectangular in cross-sectional configuration, said lens is rectangular in planar configuration, and said refractor is configured in the shape of a frustum of a four-sided hollow pyramid.
 7. The structure of claim 2 wherein a reflector is disposed above said light source to direct light therefrom to and through the lens.
 8. The structure of claim 2 wherein said fixture is adapted to be secured to a room ceiling, said base being secured directly to such ceiling.
 9. The structure of claim 2 wherein said fixture is adapted to be secured to a room ceiling, said housing being secured directly to such ceiling.
 10. The structure of claim 2 wherein said fixture is adapted to be pendantly secured to a room ceiling.
 11. The structure of claim 2 wherein said housing is annular in cross-sectional configuration, said lens being annular in planar configuration and resting on the refractor, said refractor being configured in the shape of a frustum of a hollow cone, the sides of said refractor extending downwardly and outwardly at an angle of 80* to the horizontal, there being a reflector secured to the base and disposed above he the light source to direct light therefrom to and through said lens, said fixture adapted to be secured to a room ceiling with said base being secured directly to such ceiling, and said housing being detachably secured to said base by tensioned coil springs. 